Sear mechanism for guns



Feb. 22, 19,27.

w. AT. GORTON SEAR MEGHANISM FOR GUNS Filed July 1lJ lill/lll h 2 Sheets-Sheet 2 :Jn/vento@ Quorum* Patented Feb. 22, 1927.

SEIAZR, MECHANSM FOR GUNS.

Application filed July 171,

(GRANTEDUNDER THE AST OF4 The subject of this invention is a Sear mechanism for guns. Y Y

InI mounting machine guns on aircraft,A it is-customary to operate theA gun by means of a trigger motor adapted for synchronized fire4 and mounted exterior to theV gun, while-pro--l vision may be made in the gun casing'for attaching the triggerI motor to either side of thegunto be readilyinterchangeable with a hand trigger. Consequently,- the slide for rel-easing the sear from the` firing-pin must be operable from either side of the gun and' is, ordinarily so constructed that a considerable` thrust is required to release the sear. This condition not only necessitates an eX ceedingly strong construction in the synchronizing gear, results inthe use of an ap-V preciableamount of power, occasional breakage and frequent loss of adjustment, but is not desirable when the gun is operatedv by a hand' grip on account of the amount of trigger pull which would have to be exerted. 'A considerable advantage, therefore, acf crues when ammuch easier sear release is provided but such animprovement must be. effected` Without increasing the probability ofi' accidentall release of the sear dueto faulty holding. The usual procedure has been` to`v have the sear engage they iiring pin at an.V

angle ofy 90' and to depend. uponthe scar being held 'in engagement by action of a spring. Release of the sear has been effectedl by a. sliding member which cams the sear out of engagement with the iiringpin when: thrust inward by the action of the trigger, while reengagement of the sear vandreturn movement offthe-sear slide have been accom-V plished by a spring.j

`My invention resides in the changingV of". l

'position by a .scar spring. l5, mounted on. aa 95 they sear engaging surfaces of' thefliring pin andthe corresponding surfaces of the. sear' to all-O- plane with respect totheaxs of the firing pin to release the sear'upon application of? a relativelylight thrust., and` indesngni-ng the sear and sear'slidc so that the'- actionl of the sear slide will be to positiveljyjl loclrv the sear in cockedY position, and to. permit the ring pin to disengage the seau-atV the. proper point in movement of the sear slide.- 1, also, construct the sear slide and its spring so that they may be reversed, the spring *being* then, mounted on the opposite sideof' the bolt, tov permit of operation by the tripelement located onfeitheriside of the reference:

`respon'dingly beveledA .surface 1,9 vin 1924. sei-iai No. 725,442.

MARGH s, issa; 22 STAT. L. 6,25.)

To these and other ends, my invention confsists in the construction, arrangement, and combination of elements, described herein. after and pointed out in the claims forming a part of this specification.

lpractical embodiment of my vinvention is illustrated in the accompanying drawings, in which, i Fig. l is a top plan view of a gun broken to show the arrangement of trip'l and sear slide; y

FiO'. 2 is a. longitudinal sectional View showing the sear disengaged from the firing. pin and the slide in unlocked position.

Fig. 3is a sectional view taken on the line 3 3 of-Fig. 2;, Y l

Fig. 1li is a plan view.A of the slide;

Fig. 5 is a view of the slide inelevation;

Fig. 6 is a perspective of the sear;

Fig. Tis a sectional View takenV oni the line 4"-7 ofFig. 6,5 i

Fig. 8 Lis a sectional view takenI on line. 8 8 of Fig. 6; and

Fig. 9 is'a longitudinal the tiring pin.

Referring to the drawings. by numerals'of sectional view ofy l() indicates the sideY plates ofthe. machine? gun between whichreciprocates the bolt 1F11. formed with a longitudinal borein which is: reciprocably mounted. a firing pin l2, and. pivotally carrying the usual (Locking lever 13. Y The firing pin-.is held iny cocked. posi. tion by a sear le, which slides. vertically in slots ll', cut in the. bolt and the. lower-end verselyV in the upper surfaceof the'tiring pin. ad]acent its rear end. l Y

The sear is depressedV to its lowerlnost pin 16,V located in a suitable aperture-in thev bolt and passing through aligning slots .in the firing pin to form'the rear abutment forthe firing pin spring 17. The pin '16 is. bevf 'eled atiits pointV toA facilitate insertion. in 1.00

thel slots-in the firing pin: and seats in. a.- re- 1 cess formed inthe vbolt beneath. the firingA pin. The lower portion. of the sear 14: is formed with an. outstandingl lug lSbeveledi von its. under surface at an angle of' l5? or, 105 y anyangle less vthan 90, Vto cofact with aicorhA groove 12 ofthe firing pin.

A slide 20,- mounted. transverselyY 'of the i f bolt and having a Vsliding tinra...groove1l0' of which seats. in a groove l2 cut trans.7

. the.

formed therein, rides on the lug 18 of the sear and is normally projected in line with a trip element by a spring 21, mounted on a pin 22,

as clearly shown in Fig. 2, whereby to prevent lateral displacement of the pin. One end of the slide is recessed as at 20 to form a seat for the slide spring 21, while the under portion is cut away as at 22 to form a groove which is slightly wider than the lug 18 and into which the lug is permitted to riseV when the slide has been actuated by the trip elcment. The slide is further formed with opposite projections 23, which are so posi tioned with respect to the groove 22 that one of them will engage one side of the sear and limit the lateral movement ot the slide and the action of the slide spring at a point where the groove 22 'will be to Vone side of the lug 18. The slide isso formed that lit may be reversed ttor operation trom either side of the gun. Y Y Y Upon recoil o t the bolt, the cooking lever 13 retracts the firing pin against the tension of the iii-ing pin sprino- 17 until the sear under :torce of its spring is depressed into the groove 12 orp the tiring pin. VWhen the sear has been depressed clear of the groove V22( in the slide, the slide will be tree to be moved laterally by its spring, the lowermost portion in the slide riding on the lug 18 of the sear and positively locking the sear and ring pin in cocked posit-ion. Vhen the slide is actuated by the trip elenient, the groove 22 of the slide will be positioned oppositethe lug 18 of the sear, when by reason o the lbeveled surfaces of the lug 18 and groove 12 of the firing pin, the firing pin under the influence of the firing pin spring will cam the sear out ot engagement and-into the groove `22 and be released to firing position. Y

Removably mounted on either ot the side plates is a trip housing 24C, which is clianneledto enclose a trip element 25 reciprocably mounted within the housing adjacent the side plate and normally niaintainedl in idle position by a sprinv' 2 rlfhertrip 25 is operatively engaged with a trigger 27 by means of a lug 28 on its rear end while its front endis terminated by a T-head, one wing of which is formed with a beveled face extending through an aperture in the side plate and adapted to actuate the slide 20, while the other wing is adapted to seatV the forward end ofthe spring 26.

l/Vhile in the foregoing there has been illustrated andV described such combination and arrangement of elements as constitute the preferred embodiment' of my invention, it is nevertheless desired to emphasize the fact that interpretation of the invention should only be conclusive when made in the n light 'of thesubjoined claims.;`V

carried by the bolt and recessed for engagement by the sear spring pin 1GV I claim:

l. A machine gun embodying a bolt, a firing pin, a firing pin spring, a cooking lever carried by the bolt and adapted to retract the firing pin, a sear slidabiy mounted on the bolt, a spring engaging the sear, a pin carried bythe bolt and extending through nthe firing pin for retaining the sear spring pin, and means retract the tiring pin, a sear slidably mounted Y on the bolt, a spring, engaging the sear, means vtor retaining both the sear spring and firing pin spring, a slide adapted to ride on a portion oi5 the sear, said slide formed Y with a groove on its lower side, a stop formed onthe slide and adapted to engage the sear, a spring engaging the slide, a pin carried by the bolt torreta'ining said spring, said pin formed with a recess to receive the sear spring retaining means, and means for actuating theslide. i

8. A machine gun embodying a` bolt, a

firing pin, a firing `pin spring, agcocking lever carried bythe bolt and adapted to -retract the firing pin, a vsear slidably mounted on thebolt',a spring engaging the sear, a pin carried by the bolt and extending through the firing pin Vtor retaining'both the sear spring and firing pin spring, a slide adapted i to ride on a portion of the sear, saidl slide formed with a groove on its lower side, stops termed on the slide'and adapted to engage the sear, means :tor normally forcing onel ofthe stops against the sear, and means for actuating the slide.`

4. liir'ii'iachineV gun embodying'V a bolt, a` tiring pin, a firing pin spring, a cooking lever carried by the bolt and rengageable with the tiring pin, a Vsear slidably mounted Von theV bolt, said sear formed Vwith alug,

means ior depressing the sear into engagement withthe ring pin, a slide adapted to ride on the lug ot the sear, said slide formed with a groove on its lower side, a stop Vformed on the slide and adapted to engage the sear, means for normally positioning the slide so that the lug of the sear Will be out of line with the groove of the slide, and

means tor aligning the lug and groove of the slide. y

5. A machine gun embodying a bolt, afiring pin carried by the bolt, said tiring pin formed with a` groove having a beveled rear wall, means for cooking the tiring pinka.:

lli).

v mally depressing sear slidably mounted on the bolt, a lug formed at the bottom of the sear and having its under surface beveled, means for nor the firing pin, means adapted to ride on the lug for locking the firing pin in cocked position, said means being formed with a groove, means for normally maintaining the aforesaid means in locking position, means for positioning the locking means in unlocked relation to the sear, and means carn Iried by the tiring pin for automatically actuating the firing pin when the looking means are in unlocked relation to the sear.

6. In a machine gun, the combination With a bolt, a tiring pin and a cooking lever, of a sear adapted to engage the firing pin by a surface less than av right angle, means for depressing the sear int-o engagement With the tiring pin, reversible means engageable with the sear for normally locking the sear andv tiring pin in engagement, said means being formed to provide a clearance for the sear when in unlocked relation to the sear, means for positioning the aforesaid means in unlocked relation to the sear, and means for automatically actuating the tiring pin when the locking means are moved to un-` locked position.

7. In a machine gun, the combination with a bolt, a firing pin and a cooking lever, of means adapted to engage the firing pin When the same is retracted, a reversible slide engageable with the aforesaid means for normally locking the same in firing pin engagement, said slide being formed to provide clearance for said means When in unlocked `relation thereto, means for moving the slide to unlocked position, and means for automatically releasing the firing pin when the slide is moved to unlocked position.

8. In a machine gun, the combination With a bolt, a tiring pin and a cooking lever, of means adapted to normally engage the firing pin when the same is retracted, reversible means for locking the aforesaid means in iiring pin engagement said means being adapted to be automatically moved into lockthe lug into the groove of` ing position, and manually moved to unlocking position, and means for automatically releasing the tiring pin.

9. In a machine gun unit, a bolt, a firing pin reciprocally mounted Within the bolt, means for cooking the firing pin, a sear engageable with the firing pin to hold it in cocked position, a reversible slide for locking the sear, means for actuating the slide, and means for automatically releasing the firing pin.

lO. In a machine gun unit, including a sear, a reversible sear locking slide formed with opposed stops, and a slide operating mechanism securable on either' side of the gun.

ll. In a machine gun unit, a sear, a slide engageable with the sea-r, a stop formed on the slide and adapted to engage the sear, said slide having a groove positioned with respect tothe stop so that the groove Will be out of line With thersear when the stop engages the sear, and means for actuating the slide.

l2. In a machine gun unit, a bolt, a tiring pin reciprocally mounted Within the bolt, a spring carried by the firing `pin, means for cooking the firing pin, a sear engageable with the tiring pin to hold it in cocked position, a sear spring, a pin for retaining the sear spring and tiring pin spring, aslide, a slide spring and a pin for retaining the slide spring, said pin formed with a recess to receive the firstmentioned pin, whereby to prev-ent lateral displacement.

I3. In al machine gun unit, a bolt, a liring pin reciprocally mounted Within thel bolt, means for cooking the firing pin, a sear engageable With the firing pin to hold it in cocked position, and al member slidable in either direction transversely of the bolt to lock the sear.

lil. The combination with a breech bolt,

of a sear carried by the bolt,and a sear lock,

said lock reversible whereby it may be operated 1n reversed directions to release the sear. t

WALTER T. GORTON. 

